This invention is concerned with roller units, particularly roller units that may be employed as casters for luggage.
One type of roller unit employed heretofore as a caster for luggage comprises a one-piece metal housing having a roller-receiving shell formed by a series of metal working operations which draw the shell from a metal strip and bring it to size gradually. At the end of the draw a final trim-out provides the proper shell opening, and then an additional piercing or drilling operation produces holes in the shell for a shaft on which the roller rotates. This type of roller unit has certain disadvantages, including the following: the base of the unit has a hole where the shell is drawn from the base; the metal of the formed shell is thinned out due to the drawing operation; secondary operations are required for trimming out and hole-piercing or drilling. Other types of roller units have other disadvantages, such as housings with multiple parts that must be assembled, or housings that have insufficient strength.